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The family Therizinosauridae was coined by Evgeny Maleev in 1954 to contain the enigmatic Therizinosaurus cheloniformis, which Maleev originally thought to be a species of giant "turtle-like lizard."[1] It was long considered a strange, probably carnivorous, species. Relatives of Therizinosaurus were later found but not recognized as such for some time. These more complete specimens were herbivores, and had a bizarre mixture of what looked to early researchers like a mix between ornithischian and "prosauropod" dinosaurs. Collectively, these were included in the family Segnosauridae, or "slow lizards", due to their heavy bodies, short legs, and presumably slow, ground sloth-like lifestyle.[2] Subsequent studies found that segnosaurids were neither prosauropods nor ornithischians, but actually bizarre theropods, and that the previously enigmatic Therizinosaurus was also a member of this group. Since the family Therizinosauridae was named earlier than Segnosauridae, the later name became a junior synonym of the former, despite the fact that Therizinosaurus was a new addition to the segnosaurid group.[3]